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WASHINGTON — A long-awaited nutrition report suggests lowering the maximum amount of salt Americans should allow themselves each day, even though the average person already consumes far more than is recommended.

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But don’t worry about water, the report says; people easily get plenty, so let thirst be your guide instead of counting glasses. If you prefer coffee or soda, all beverages, even those with caffeine, count toward the daily water allotment, says Wednesday’s report from the Institute of Medicine.

The institute is a scientific organization that sets the nation’s recommended levels of nutrients. Its salt conclusion could bring a dramatic change to the sodium content consumers see on the labels of their favorite foods.

The government currently recommends no more than 2,400 milligrams of sodium a day, the equivalent of a heaping teaspoon of salt. The new recommendation is 1,500 mg a day.

Yet studies show the average person eats more than 4,000 mg a day, three-quarters of it from restaurant meals and common processed foods like spaghetti sauce and frozen dinners.

“We don’t have our heads in the sand on this one. We realize where we are is quite a distance from where we should be, ... and there are commercial interests that don’t want this to happen,” said Dr. Lawrence Appel, a professor of medicine at Johns Hopkins University, who led the institute panel.

“People can cook and prepare Western-style diets that are at that level” even though “it will take work right now,” Appel said.

The Food and Drug Administration uses the institute’s nutrient levels to calculate food labels’ listing of the percentage of the daily allotment of fat, vitamins and other substances occurs in each serving. The FDA wouldn’t say how quickly it would update sodium content; changing food labels typically takes several years.

As an example, a popular brand of canned clam chowder that provides 36 percent of daily sodium under today’s guidelines would provide 57 percent of the new level. For some chips, sodium content would change from 15 percent under today’s guidelines to 23 percent.

The adage “drink at least eight glasses of water a day” is unnecessary. The average healthy person gets plenty of fluid, from beverages as well as the water content of fruits, vegetables and other fluids. So don’t bother counting, just drink when thirsty.

Most Americans need to eat a lot more potassium — 4,700 mg a day, roughly double current consumption. Potassium is found in bananas, spinach, cantaloupe and numerous other fruits and vegetables; food sources are better than supplements. Potassium lowers blood pressure and reduces the risk of kidney stones and bone loss.

The food industry opposes the salt change, and the U.S. Chamber of Commerce, working with the Salt Institute, is questioning one of the government studies used to derive it.

“Dietary recommendations for all Americans need to be realistic,” said Stephanie Childs of the Grocery Manufacturers of America.

Childs said consumers wouldn’t buy foods that suddenly drop sodium levels because they would taste different, but companies are hunting for new recipes to provide a gradual decline. Some already have: Canned foods today contain 40 percent less sodium than a few years ago, she said.

Blood-pressure specialists welcomed the Institute of Medicine’s new recommendation, saying even if consumers don’t get down to 1,500 mg of daily sodium, every little decline helps.

“The data’s strong,” said Dr. Daniel Jones of the American Heart Association. “These are certainly healthy goals. They will be a challenge for individuals to achieve, but they can be achieved.”

The American Public Health Association is pushing for the sodium in processed foods to be halved within 10 years. The new guidelines mean “the food industry really has to take this issue much more seriously now,” said Dr. Stephen Havas of the University of Maryland, who is leading that call.

The 1,500-mg salt level is the level for healthy younger adults. Because blood pressure rises with age, the new report says people over 50 should strive for 1,300 mg, and 1,200 mg for those over 70.